Turning off anti-aliasing: inconsistency between 'info' window and valid python commands

Question

I want to render an image without anti-aliasing. Using the UI, I select the Workbench engine. Then, under Sampling, I set Render to No Anti-Aliasing.

This displays the following commands in the info window:

bpy.context.scene.render.engine = 'BLENDER_WORKBENCH'
bpy.context.scene.render_aa = 'OFF'

When I try the same commands in the console, or in a stand-alone script, I get the following error:

AttributeError: 'Scene' object has no attribute 'render_aa'

Why is the info window lying to me?

Further, how can I turn off anti-aliasing in the Workbench engine with python?

Answer 1

The anti-aliasing for the Workbench engine can be turned off through:

bpy.context.scene.display.render_aa = 'OFF'

The API manual is very helpful for cases where the Python command is unclear. The render_aa property is part of the class bpy.types.SceneDisplay. Searching for this type shows that bpy.context.scene contains a reference to an object of that type.

The reason why the command is displayed incorrectly seems related to T69803. The Python tooltips are incomplete for PropertyGroups because RNA_path_full_property_py_ex()(rna_access.c) doesn't return a full path. This is also the reason why you see Python tooltips with missing parts like bpy.data.scenes["Scene"] ... render_aa for the Render anti-aliasing property in the UI.

TL;DR It's a bug.